tjh.dev
Linux kernel mirror (for testing)
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1/*
2 * Copyright © 2014 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Daniel Vetter <daniel.vetter@ffwll.ch>
25 */
26
27/**
28 * DOC: frontbuffer tracking
29 *
30 * Many features require us to track changes to the currently active
31 * frontbuffer, especially rendering targeted at the frontbuffer.
32 *
33 * To be able to do so GEM tracks frontbuffers using a bitmask for all possible
34 * frontbuffer slots through i915_gem_track_fb(). The function in this file are
35 * then called when the contents of the frontbuffer are invalidated, when
36 * frontbuffer rendering has stopped again to flush out all the changes and when
37 * the frontbuffer is exchanged with a flip. Subsystems interested in
38 * frontbuffer changes (e.g. PSR, FBC, DRRS) should directly put their callbacks
39 * into the relevant places and filter for the frontbuffer slots that they are
40 * interested int.
41 *
42 * On a high level there are two types of powersaving features. The first one
43 * work like a special cache (FBC and PSR) and are interested when they should
44 * stop caching and when to restart caching. This is done by placing callbacks
45 * into the invalidate and the flush functions: At invalidate the caching must
46 * be stopped and at flush time it can be restarted. And maybe they need to know
47 * when the frontbuffer changes (e.g. when the hw doesn't initiate an invalidate
48 * and flush on its own) which can be achieved with placing callbacks into the
49 * flip functions.
50 *
51 * The other type of display power saving feature only cares about busyness
52 * (e.g. DRRS). In that case all three (invalidate, flush and flip) indicate
53 * busyness. There is no direct way to detect idleness. Instead an idle timer
54 * work delayed work should be started from the flush and flip functions and
55 * cancelled as soon as busyness is detected.
56 */
57
58#include "display/intel_dp.h"
59
60#include "i915_drv.h"
61#include "intel_drv.h"
62#include "intel_fbc.h"
63#include "intel_frontbuffer.h"
64#include "intel_psr.h"
65
66void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
67 enum fb_op_origin origin,
68 unsigned int frontbuffer_bits)
69{
70 struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
71
72 if (origin == ORIGIN_CS) {
73 spin_lock(&dev_priv->fb_tracking.lock);
74 dev_priv->fb_tracking.busy_bits |= frontbuffer_bits;
75 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
76 spin_unlock(&dev_priv->fb_tracking.lock);
77 }
78
79 might_sleep();
80 intel_psr_invalidate(dev_priv, frontbuffer_bits, origin);
81 intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits);
82 intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin);
83}
84
85/**
86 * intel_frontbuffer_flush - flush frontbuffer
87 * @dev_priv: i915 device
88 * @frontbuffer_bits: frontbuffer plane tracking bits
89 * @origin: which operation caused the flush
90 *
91 * This function gets called every time rendering on the given planes has
92 * completed and frontbuffer caching can be started again. Flushes will get
93 * delayed if they're blocked by some outstanding asynchronous rendering.
94 *
95 * Can be called without any locks held.
96 */
97static void intel_frontbuffer_flush(struct drm_i915_private *dev_priv,
98 unsigned frontbuffer_bits,
99 enum fb_op_origin origin)
100{
101 /* Delay flushing when rings are still busy.*/
102 spin_lock(&dev_priv->fb_tracking.lock);
103 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
104 spin_unlock(&dev_priv->fb_tracking.lock);
105
106 if (!frontbuffer_bits)
107 return;
108
109 might_sleep();
110 intel_edp_drrs_flush(dev_priv, frontbuffer_bits);
111 intel_psr_flush(dev_priv, frontbuffer_bits, origin);
112 intel_fbc_flush(dev_priv, frontbuffer_bits, origin);
113}
114
115void __intel_fb_obj_flush(struct drm_i915_gem_object *obj,
116 enum fb_op_origin origin,
117 unsigned int frontbuffer_bits)
118{
119 struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
120
121 if (origin == ORIGIN_CS) {
122 spin_lock(&dev_priv->fb_tracking.lock);
123 /* Filter out new bits since rendering started. */
124 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits;
125 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
126 spin_unlock(&dev_priv->fb_tracking.lock);
127 }
128
129 if (frontbuffer_bits)
130 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, origin);
131}
132
133/**
134 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
135 * @dev_priv: i915 device
136 * @frontbuffer_bits: frontbuffer plane tracking bits
137 *
138 * This function gets called after scheduling a flip on @obj. The actual
139 * frontbuffer flushing will be delayed until completion is signalled with
140 * intel_frontbuffer_flip_complete. If an invalidate happens in between this
141 * flush will be cancelled.
142 *
143 * Can be called without any locks held.
144 */
145void intel_frontbuffer_flip_prepare(struct drm_i915_private *dev_priv,
146 unsigned frontbuffer_bits)
147{
148 spin_lock(&dev_priv->fb_tracking.lock);
149 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits;
150 /* Remove stale busy bits due to the old buffer. */
151 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
152 spin_unlock(&dev_priv->fb_tracking.lock);
153}
154
155/**
156 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
157 * @dev_priv: i915 device
158 * @frontbuffer_bits: frontbuffer plane tracking bits
159 *
160 * This function gets called after the flip has been latched and will complete
161 * on the next vblank. It will execute the flush if it hasn't been cancelled yet.
162 *
163 * Can be called without any locks held.
164 */
165void intel_frontbuffer_flip_complete(struct drm_i915_private *dev_priv,
166 unsigned frontbuffer_bits)
167{
168 spin_lock(&dev_priv->fb_tracking.lock);
169 /* Mask any cancelled flips. */
170 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits;
171 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
172 spin_unlock(&dev_priv->fb_tracking.lock);
173
174 if (frontbuffer_bits)
175 intel_frontbuffer_flush(dev_priv,
176 frontbuffer_bits, ORIGIN_FLIP);
177}
178
179/**
180 * intel_frontbuffer_flip - synchronous frontbuffer flip
181 * @dev_priv: i915 device
182 * @frontbuffer_bits: frontbuffer plane tracking bits
183 *
184 * This function gets called after scheduling a flip on @obj. This is for
185 * synchronous plane updates which will happen on the next vblank and which will
186 * not get delayed by pending gpu rendering.
187 *
188 * Can be called without any locks held.
189 */
190void intel_frontbuffer_flip(struct drm_i915_private *dev_priv,
191 unsigned frontbuffer_bits)
192{
193 spin_lock(&dev_priv->fb_tracking.lock);
194 /* Remove stale busy bits due to the old buffer. */
195 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
196 spin_unlock(&dev_priv->fb_tracking.lock);
197
198 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, ORIGIN_FLIP);
199}